Filipino fishermen operate around Scarborough Shoal in the South China Sea while Chinese vessels stay in the distance.

SCARBOROUGH SHOAL, South China Sea--In the predawn darkness, four lights flicker on the horizon.

"Four Chinese ships," says one of the Filipino fishermen ominously.

We are 200 kilometers or so west of Infanta, a fishing village in the northern Philippines, from which we departed 19 hours earlier, and close to disputed Scarborough Shoal in the South China Sea.

As the sun rises Dec. 13, rocks poke through the sea surface. This rich fishing ground is at the front line of a territorial row that pits China against the Philippines and Taiwan.

The shoal may be nothing more than a pile of rocks and coral reefs, but it is of immense strategic interest to China, which seems intent on reclaiming it to construct a military stronghold. It has done the same with seven other artificial islands in the South China Sea.

Two Chinese vessels are painted white and have the words “China Coast Guard” emblazoned in capital letters on their sides. The other two ships are painted blue, denoting Chinese patrol boats, according to the Filipino fishermen.

Our 10-meter-long boat is dwarfed in size by the Chinese ships.

We navigate inside the doughnut-shaped Scarborough Shoal, but the Chinese vessels stay where they are.

When the Philippine captain, Juanito Rebios, arrived in late November, the Chinese ships behaved quite differently. Rebios, 41, recalled that an inflatable carrying seven Chinese clad in black uniforms approached his boat. One of them, holding a gun, instructed him in English to leave the area, saying it was a final warning.

“It was really terrible," Rebios said. "Sometimes, the Chinese allow us to fish, and other times they order us to stop. We never know when they are going to approach us.”

The situation these days is a far cry from before 2012, the year China began to effectively control Scarborough Shoal.

Fishing boats from the Philippines, Vietnam, China and Hong Kong freely operated around Scarborough Shoal.

But from 2012, Rebios and his crew were repeatedly expelled from the waters by Chinese ships firing water cannons.

China ceased interfering after Rodrigo Duterte became president of the Philippines in June. This was due to his pro-China stance, which was evident in his meeting with Chinese President Xi Jinping that October.

However, China continues to interrupt Filipinos’ fishing operations on a sporadic basis. So Filipinos fish here when they can, while fearful of China.

Tensions heightened in the South China Sea on Dec. 15 when a Chinese naval vessel seized a U.S. Navy underwater drone in an area south of Infanta.

Scarborough Shoal lies within the exclusive economic zone (EEZ) of the Philippines. However, it is claimed by not only the Philippines but also China and Taiwan.

In July, the Permanent Court of Arbitration, based in The Hague, denied China’s claim over the South China Sea. As for Scarborough Shoal, the court said that China is infringing on the Philippines’ traditional fishing rights there.

China has refused to accept the court ruling.

In September, 10 Chinese ships were spotted around Scarborough Shoal. Some of them appeared to be dredging boats, raising concern that China may start to reclaim the area.

“If (other countries) do nothing, China will construct a military base in Scarborough Shoal. But if the United States takes a strong stance against China, it will be us who are involved in the dispute between the United States and China,” said Rebios.

(This article was written by Akiko Suzuki and Takaharu Yagi.)